1. Field of the Invention
The present invention relates to a quad-axial force and torque measurement sensor; more particularly, the present invention relates to a quad-axial force and torque measurement sensor with high sensitivity and thin thickness.
2. Description of the Related Art
Piezoelectricity results from the conversion of mechanical energy, such as pressure causing a deformation of the piezoelectric material, to electricity; conversely, electricity applied to a piezoelectric material will be converted to mechanical energy. Since the discovery of the piezoelectric property of barium titanate (BaTiO3) in 1942, research on piezoelectric materials has developed well, and many kinds of piezoelectric applications have been disclosed; for example, piezoelectric materials can be used for producing piezoelectric thin films to form a sensing element.
The most common piezoelectric ate al is the inorganic ceramic (such as barium titanate and lead zirconate titanate). An inorganic ceramic has the features of small volume, great response speed, and low power consumption for displacement. However, the uses of piezoelectric materials are limited. For example, since piezoelectric materials are brittle, the structure of the piezoelectric thin film may fracture easily when sustaining an uneven force. In addition, since inorganic piezoelectric materials are hard, brittle and heavy, it is difficult and expensive to produce a thin and small thin film or a thin film with a complex shape. Also, because the piezoelectric thin film of the prior art can only sense changes in one or two directions (such as an X axis and a Y axis), it is difficult to sense changes in three or more directions.
Therefore, there is a need to provide a new piezoelectric thin film sensor made of piezoelectric material and having high sensitivity and thin thickness that can sense changes on four axes.